View Full Version : Voltage regulation again?

06-14-2006, 10:43 PM
Okay, so a little over a year ago, not long after I got the truck, I replaced the voltage regulator because the headlights were fading in and out, ammeter was jumpy etc. It's been fince since, once I adjusted it so that it allowed the proper voltage to reach the battery.

Tonight we found out that at idle the voltage was sitting around 14.7, and then I revved the engine a little and it jumped up to around 16, and then when I let off the throttle it returned back down to about 13.8.

The battery's cells have signs of boiling off, and the cells were pretty low on water. It's been a while since I've checked them, but the battery isn't very old, no more than a year. I'm having a hard time believing the voltage regulator is bad already, so does anybody have any ideas? Can I just adjust it down a bit? Maybe I thought I had it adjusted correctly before and maybe it wasn't...

06-15-2006, 11:32 AM
Mark Whatley has an excellent write up in his Tech Exchange in the March/April 2006 issue of Toyota Trails. A possible cause of your symptom is that the contact points inside the regulator are intermittently sticking closed. If you have that issue of Toyota Trails, read his write up. After reading it, you will have a much better idea of what to do.

BTW, I do not completely agree with his assessment of normal voltage, I prefer to see a little lower voltage than he describes. I like to see 13.5-13.8 at idle and 13.8-14.2 above idle. IMHO, much above 14.5 for extended periods is going to wear out the battery prematurely.